A Drover from the Snowy Mountain region in southern New South Wales sits on his horse outside New South Wales state parliament October 12 in protest at the government's pending decision on the water flow of the Snowy River.Reuters

An Australian plan to euthanize thousands of wild horses in the northern region has appalled conservationists the world over.

The New South Wales government has decided to kill more than 5,000 brumbies in the Snowy Mountains as part of a plan to cut down the number of wild horses by 90 percent in the next 20 years.

The horses are central to the region's folklore and have a special significance in the cultural history of Australia, a country said to have been "built on horseback."

The brumbies were even featured at the opening ceremony of the 2000 Sydney Olympics.

However, in their homeland in the north, the brumbies are blamed for highway crashes, destruction of endangered native species and damage to waterways.

While admitting that the issue is complex, the state's Environment Minister Mark Speakman told BBC that the plan will be adhered to.

"There are diverse opinions in the community and often deeply held views, which polarise stakeholder groups .. It is clear, however, that the broader community values the unique environmental values of Kosciuszko National Park," he said.

Officials said methods like trapping, ground shooting and fertility control will be used to control the population. Fencing, re-homing and mustering will also be used as part of a draft plan to move the brumbies from the region.

The latest push to the brumby control plan came in the way of two fatal traffic crashes last year.

A teenage boy was killed when a car he was travelling in hit a brumby carcass on the highway in northern Queensland. The death, the second caused by a brumby collision in two months, raised calls for reducing the population of the Snowy Mountain feral horses.

"They need to cull these animals. They are feral pests along with pigs and the wild dogs that we have in the area and they need to be treated the same," Townsville councilor Sue Blom told Brisbane Times.

But the Australian Brumby Alliance said the move to cull the animals was a "kneejerk" reaction.

Jill Pickering, the associations' president, said alternatives to euthanasia should be sought, including re-homing the brumbies.

Following strong calls for limiting brumby related accidents on the highways, Queensland National Parks Minister Steven Miles said in October the horse slaying plan was in place.

"We have experimented with a whole range of different options, but they have tended to result in poor animal welfare outcomes," the minster said, according to BBC.

There are around 400,000 wild horses on the Australian continent, acceding to the government estimates. Most of these wild animals are in the Northern Territory and Queensland.